C T McBride writes: : | A little more tinkering, and it looks like it might be | | show :: Show (f (Wonky f)) => Wonky f -> String | | Is this really the type of show? That looks correct to me. | If so, no wonder there's a problem. Yes, there's a vicious circle in context reduction, between Wonky Copy and Copy (Wonky Copy). | I don't want to start an argument about how to solve this problem. I | do want to suggest that, for the time being, it would be better to | reject `deriving Show' for type constructors like Wonky (ie those with | higher-kind parameters) than to generate instances which break the | compiler. | | Or am I just being a spoilsport? It depends on your definition of sport. ;-)
data Sport f = Sport | Association (f Bool) deriving Show
test = show (Sport :: Sport Maybe)
Regards, Tom